Vega VEGACAP 65 Operating Instructions Manual page 13

Pressure/Vacuum
Vessel material
Condensation
Cable entries - NPT
thread
Cable glands
VEGACAP 65 • Two-wire
applies mainly to outdoor mounting as well as installation in areas
where high humidity is expected (e.g. through cleaning processes) or
on cooled or heated vessels.
To maintain the housing protection, make sure that the housing lid is
closed during operation and locked, if necessary.
Fig. 4: Measures against moisture ingress
The process fitting must be sealed if there is gauge or low pressure
in the vessel. Before use, check if the sealing material is resistant
against the measured product and the process temperature.
The max. permissible pressure is specified in chapter " Technical
data" or on the type label of the sensor.
Metal vessel
Make sure that the mechanical connection of the probe to the vessel
is electrically conductive to ensure sufficient grounding.
Use conductive seals, such as those made of copper or lead, etc.
Insulating measures, such as covering the thread with Teflon tape,
can interrupt the necessary electrical connection with metal vessels.
For this reason, ground the probe on the vessel or use a conductive
seal material.
Non-conductive vessels
In non-conductive vessels, e.g. plastic tanks, the second pole of the
capacitor must be provided separately.
If condensate forms on the vessel top, the run-off liquid can cause
bridging and hence faulty switchings.
For this reason, use a screening tube or a longer insulation. The
length depends on the amount of condensate and the drain-off be-
haviour of the product.
Metric threads
In the case of instrument housings with metric thread, the cable
glands are screwed in at the factory. They are sealed with plastic
plugs as transport protection.
You have to remove these plugs before electrical connection.
4 Mounting
13